Portable power stations: size for the outage, not the wattage
The number on the box is output watts. The number that decides whether you get through a night is watt-hours. Most buyers compare the wrong figure and end up with a unit that runs a kettle beautifully and a fridge for four hours.
Do the outage arithmetic first
Write down what you would actually run, and for how long. A modern fridge draws 40-80W average once running (surge on compressor start can hit 300-600W), a CPAP is 30-60W, a laptop 50W, a few LED lights 20W, a router 15W. Twelve hours of that load is often 1.2-1.8 kWh — and a 1,000Wh station gets you most of the way through one night, not two days.
| Typical load | Running watts | kWh over 12 hours |
|---|---|---|
| Fridge (average duty cycle) | 40-80 | 0.5-1.0 |
| CPAP | 30-60 | 0.4-0.7 |
| LED lights ×4 | 20 | 0.24 |
| Router + ONT | 15 | 0.18 |
| Phone and laptop charging | 60 | 0.7 |
Surge, not just continuous
Motors and compressors draw multiples of running current for a fraction of a second. A station rated 1,000W continuous may handle 2,000W surge, which covers most fridges but not a well pump. Check both figures, and check whether the surge rating is for a fraction of a second or several seconds.
Recharge speed is the quiet differentiator
A big battery you cannot refill is ballast. Look at AC recharge time (units with fast charging fill in 1-2 hours, others take 8-10), solar input limits, and whether the unit can charge and discharge simultaneously, which matters for continuous backup. LiFePO4 units generally hold their recharge curve much better than older NMC designs.
What separates good units from cheap ones
LiFePO4 cells rather than NMC where longevity matters; a documented cycle life at 80% capacity; UPS-grade switchover under 20ms if you want to protect a desktop or medical device; a regulated output that holds voltage as the battery drains; and a warranty that names the cycle count. A 500-cycle pack is a different product from a 3,000-cycle pack even when both say "lithium".